It is possible that you have a bench warrant from your old case. It is important that you retain a defense attorney experienced in DUI cases who will be able to determine what happened with your old case and secure the best result on your new case.
I suggest you hire an attorney and discover why it took two year. ARD is for first time offenders and you should be able to enter the ARD program. But talk to an attorny and provide all facts so that if you have a defense, that defense can be pursued.
It depends on what happened 2 years ago. If you have any type of a prior record (conviction or ARD) then you are not eligible for ARD. If you do not get ARD then there is mandatory jail time if your level is over .10%. If this is a second, then there could be a mandatory sentence of months in jail.
You should consult with a local attorney and tell him everything so you can get the right advice.
My website has alot of DUI information including a free 50 page book that I published entitled DUI in Pennsylvania - Useful Information Revealed from a Former Prosecutor.
Ellis B. Klein, Esquire
Young, Klein and Associates
Office throughout Montgomery and Bucks County
More information would be needed about the prior incident in order to properly assess your current situation. You should contact a criminal defense attorney in the area to discuss your case. Many, like myself, offer no charge consultations. www.fightmypadui.com. 215-256-0205.
Your situation requires a fact specific review of the record. It is impossible to tell from your question what your options might be; a criminal defense lawyer would need to carefully review the circumstances of your current charges and the prior incident. You may have a real opportunity to get a good result in your present case, and possibly a diversionary program like ARD, but your first step should be speaking with a criminal attorney.
This answer is based on general legal principles only and is not intended to provide specific legal advice. This answer is for informational purposes only and does not constitute the formation of a lawyer-client relationship. Any reader of this answer should not make decisions based upon it without first directly consulting with an attorney in person.
You should consult with an experienced DWI/DUI attorney. If you want to find one in your area here on AVVO you can select "Find a Lawyer" at the top of the page. Good luck.